Pressure medium brake system for a vehicle

Abstract

A pressure medium brake system for vehicles with an electromagnetic control valve for forming a brake control pressure that increases with an increase of the energization of the coil of the electromagnetic control valve. The control valve produces a pilot control pressure which decreases with an increase of an energizing current while a modulating converter, which supplies an adjusting force that is dependent on the difference between the pilot control pressure and an essentially constant comparison pressure and that increases with an increase of the energizing current, adjusts by means of its adjusting member the brake control pressure.

I claim: 
     
       1. A pressure medium brake installation for vehicles, which comprises an electromagnetic control valve means for producing a brake control pressure that increases with an increase of the energizing magnitude of the electromagnetic control valve means, characterized in that the control valve means is operable to produce a pilot control pressure decreasing with an increase of the energizing current of the electromagnetic control valve means, and modulating converter means operable to supply an adjusting force dependent essentially on the difference between the pilot control pressure and an essentially constant comparison pressure and increasing with an increase of the energizing current, said modulating converter means including adjusting means being operable to adjust the brake control pressure. 
     
     
       2. A brake installation according to claim 1, characterized in that said adjusting means includes an adjusting slide valve member operable to adjust the brake control pressure. 
     
     
       3. A brake installation according to claim 1, characterized in that said control valve means includes a magnet part and a valve part separated from one another in a pressure medium-tight manner by a diaphragm means disposed therewithin. 
     
     
       4. A brake installation according to claim 3, characterized in that said magnetic part includes an essentially pot-shaped electromagnet which includes a first pole shoe means adjacent the diaphragm means. 
     
     
       5. A brake installation according to claim 4, characterized in that said first pole shoe means is of circular ring shape and is arranged directly adjacent the diaphragm means, said first pole shoe means forming together with an armature means of the electromagnet part of first substantially ring-shaped magnetic gap. 
     
     
       6. A brake installation according to claim 5, characterized in that said armature means is in the form of a conical pin member which is connected by way of a connecting pin with a support arm means in the valve part. 
     
     
       7. A brake installation according to claim 6, characterized in that the diaphragm means is centered on said connecting pin. 
     
     
       8. A brake installation according to claim 6, characterized in that said valve part includes a closure valve means, and in that said support arm means is essentially T-shaped and includes an essentially longitudinal beam member with two diametrally arranged cross webs forming together with abutment pins in the first pole shoe means a knife edge bearing in such a manner that the pivot axis of the system formed by the armature means and the closure valve means is located at least approximately in the plane of the diaphragm. 
     
     
       9. A brake installation according to claim 8, characterized in that the mass center of the system consisting of armature means and closure valve means is located at most only slightly displaced from the point of intersection of the pivot axis with the symmetry axis of the system. 
     
     
       10. A brake installation according to claim 8, characterized in that the end of the armature means opposite the diaphragm means is constructed essentially spherically segmentally shaped. 
     
     
       11. A brake installation according to claim 8, characterized in that a second pole shoe means is provided in the magnet part facing the end of the armature means opposite the diaphragm means, said second pole shoes means being arranged eccentrically to the symmetry axis of the system so that a second magnet gap results. 
     
     
       12. A brake installation according to claim 11, characterized in that the second pole shoe means is constructed plug-like and is operable to be selectively rotated. 
     
     
       13. A brake installation according to claim 11, characterized in that the longitudinal beam is slotted at the end near the valve closure means, and threaded means screwed into the slot of the longitudinal beam and operable as valve closure member for and cooperating with a valve seat of the valve closure means. 
     
     
       14. A brake installation according to claim 13, characterized by adjustable means for adjusting the prestress with which the valve closure member is held at the corresponding valve seat. 
     
     
       15. A brake installation according to claim 2, characterized in that the adjusting means of the modulating converter means is operable with feedback of the brake control pressure. 
     
     
       16. A brake installation according to claim 15, characterized in that the feedback is obtained by a pressure area on the adjusting slide valve member of said adjusting means. 
     
     
       17. A brake installation according to claim 1, characterized in that a pressure chamber of the modulating converter means which is adapted to be placed under the pilot control pressure and a pressure chamber of the modulating converter means which is adapted to be placed under a comparison pressure, are connected with each other by a pressure-medium filling connection means containing a throttle means effectively shut-off automatically in dependence on the pressure. 
     
     
       18. A brake installation according to claim 17, characterized in that the pressure chamber adapted to be placed under pilot control pressure and the pressure chamber of the modulating converter means adapted to be placed under comparison pressure, are separated from one another by a piston diaphragm means connected with the adjusting means. 
     
     
       19. A brake installation according to claim 18, characterized in that the modulating converter means controls a servo means interconnected between a brake control pressure line and a pressure source. 
     
     
       20. A brake installation according to claim 19, characterized in that the servo means includes a hollow slide valve means in communication with its central opening with the brake control pressure line, whose one slide valve member end is adapted to be brought into abutment at a pressure surface cooperating with the adjusting means of the modulating converter means. 
     
     
       21. A brake installation according to claim 20, characterized in that the servo means includes a common adjusting means in the form of the last-mentioned hollow slide valve means actuating an inlet valve means interconnected between the pressure source and the brake control pressure line as well as an outlet valve means interconnected between a pressure-relieved zero-connection and the brake control pressure line. 
     
     
       22. A brake installation according to claim 21, characterized in that the servo means includes a valve chamber means in communication with the zero-connection, in which a valve closure member of the outlet valve means, which is provided with the pressure surface cooperating with the slide valve member end projecting into said valve chamber means, is movably guided in the directions of the slide valve member axis. 
     
     
       23. A brake installation according to claim 22, characterized in that the last-mentioned hollow slide valve means extends through a valve chamber means of the servo means which is in communication with a connection for the pressure source, said last-mentioned valve chamber means being closed with respect to another valve chamber means in communication with a connection for the brake control pressure line, by the inlet valve means, the other slide valve member end being located in said another valve chamber means. 
     
     
       24. A brake installation according to claim 23, characterized in that said inlet valve means is ring-shaped, and in that the last mentioned hollow slide valve means actuates the ring-shaped closure member of the inlet valve means. 
     
     
       25. A brake installation according to claim 23, characterized in that the pressure surfaces at the hollow slide valve means which are influenced by the respective pressure in the valve chamber means are so matched mutually in their size that no retroactive pressure forces occur at the hollow slide valve means in the directions of the slide valve axis. 
     
     
       26. A brake installation according to claim 25, characterized in that the valve chamber means of the servo means which is in communication with the connection for the pressure source, and the pressure chamber of the modulating converter means which is adapted to be placed under the pilot control pressure, are connected with each other by a pressure medium connection containing a throttle means. 
     
     
       27. A brake installation according to claim 26, characterized in that an adjusting motor means operating with the brake control pressure and a brake pedal actuatable at will are connected with each other by way of differential actuating means. 
     
     
       28. A brake installation according to claim 27, characterized in that the differential actuating means includes a multi-circuit brake valve. 
     
     
       29. A brake installation according to claim 28, characterized in that said control valve means includes a magnet part and a valve part separated from one another in a pressure medium-tight manner by a diaphragm means disposed therewithin. 
     
     
       30. A brake installation according to claim 29, characterized in that said magnetic part includes an essentially pot-shaped electromagnet which includes a first pole shoe means adjacent the diaphragm means. 
     
     
       31. A brake installation according to claim 30, characterized in that said first pole shoe means is of circular ring shape and is arranged directly adjacent the diaphragm means, said first pole shoe means forming together with an armature means of the electromagnet part a first substantially ring-shaped magnetic gap. 
     
     
       32. A brake installation with an armature means according to claim 29, characterized in that said armature means is in the form of a conical pin member which is connected by way of a connecting pin with a support arm means in the valve part. 
     
     
       33. A brake installation according to claim 32, characterized in that said valve part includes a closure valve means, and in that said support arm means is essentially T-shaped and includes an essentially longitudinal beam member with two diametrally arranged cross webs forming together with abutment pins in a first pole shoe means a knife edge bearing in such a manner that the pivot axis of the system formed by the armature means and the closure valve means is located at least approximately in the plane of the diaphragm. 
     
     
       34. A brake installation with an armature means in the magnet part according to claim 30, characterized in that the end of the armature means opposite the diaphragm means is constructed essentially spherically segmentally shaped. 
     
     
       35. A brake installation according to claim 34, characterized in that a second pole shoe means is provided in the magnet part facing the end of the armature means opposite the diaphragm means, said second pole shoe means being arranged eccentrically to the symmetry axis of the system so that a second magnet gap results. 
     
     
       36. A brake installation according to claim 17, characterized in that the adjusting means of the modulating converter means is operable with feedback of the brake control pressure. 
     
     
       37. A brake installation according to claim 1, characterized in that a pressure chamber adapted to be placed under pilot control pressure and a pressure chamber of the modulating converter means adapted to be placed under comparison pressure, are separated from one another by a piston diaphragm means connected with the adjusting means. 
     
     
       38. A brake installation according to claim 1, characterized in that the modulating converter means controls a servo means interconnected between a brake control pressure line and a pressure source. 
     
     
       39. A brake installation according to claim 38, characterized in that the servo means includes a hollow slide valve means in communication with its central opening with the brake control pressure line, whose one slide valve member end is adapted to be brought into abutment at a pressure surface cooperating with the adjusting means of the modulating converter means. 
     
     
       40. A brake installation according to claim 38, characterized in that a servo means includes a common adjusting means in the form of a hollow slide valve means for actuating an inlet valve means interconnected between the pressure source and the brake control pressure line as well as an outlet valve means interconnected between a pressure-relieved zero-connection and the brake control pressure line. 
     
     
       41. A brake installation according to claim 40, characterized in that the servo means includes a valve chamber means in communication with the zero-connection, in which closure member of the outlet valve means, which is provided with the pressure surface cooperating with the slide valve member end projecting into said valve chamber means, is movably guided in the directions of the slide valve member axis. 
     
     
       42. A brake installation according to claim 38, characterized in that a hollow slide valve means extends through a valve chamber means of the servo means which is in communications with a connection for the pressure source, said last-mentioned valve chamber means being closed with respect to another valve chamber means in communication with a connection for the brake control pressure line, by an inlet valve means, the other slide valve member end being located in said another valve chamber means. 
     
     
       43. A brake installation according to claim 1, characterized in that an adjusting motor means operating with a brake control pressure and a brake pedal actuatable at will are connected with each other by way of a differential actuating means. 
     
     
       44. A brake installation according to claim 43, characterized in that the differential actuating means includes a multi-circuit brake valve.